Automatic reverberatory furnace charging



April 5, 1966 J. E. FOARD ETAL AUTOMATIC REVERBERATORY FURNACE CHARGING 6 Sheets-Shae 1 Filed Dec. 19, 1963 April 1966 J. E. FOARD ETAL 3,244,298

AUTOMATIC REVERBERATORY FURNACE CHARGING Filed Dec. 19, 1963 6 Sheets-Sheet 2 April 5, 1966 J. E. FOARD ETAL 7 AUTOMATIC REVERBERATORY FURNACE CHARGING Filed Dec. 19, 1965 6 Sheets-Sheet 4 6 Sheets-Sheet 5 April 5,1966 J. E. FOARD ETAL AUTOMATIC REVERBERATORY FURNACE CHARGING Filed Dec. 19; 1963 qm wt J. E. FOARD- ETAL 3,244,298 AUTOMATIC REVERBERA'I'ORY FURNACE CHARGING 6 Sheets-Sheet 6 April 5, 1966 Filed Dec. 19, 1963 United States Patent AUTOMATIC REVERBERATORY FURNACE CHARGING James E. Foard and Felix G. Berra, Morenci, Ariz., as-

signors to Phelps Dodge Corporation, New York, N .Y.,

a corporation of New York Filed Dec. 19, 1963, Ser. No. 331,829 11 Claims. (Cl. 21418) This invention relates to the feeding or charging of metallurgical furnaces, and more particularly it relates to a procedure and apparatus for automatically charging a furnace such, for example, as a reverberatory furnace used for producing copper matte.

Various devices and procedures have been used for feeding reverberatory furnaces. Such furnaces, generally, are operated continuously for long periods of time. That is, the furnace is not emptied between charges but a molten bath is maintained in the furnace at all times between the time of starting up the furnace and shutting it down for repairs or for some other reason. It is not uncommon for such a furnace to be operated continuously over a period of a year, or more, without a shutdown.

One method nOW in common use for charging a copper reverberatory furnace with the charge material to be smelted is known as side-charge smelting. In this method, it is conventional procedure for the material to be charged to the furnace to be conveyed from bins by means of drag chains, conveyor belts, vibrating conveyors, or by other devices, along each side of the furnace from a place adjacent the burner end, or bridgewall, for a distance of approximately two thirds of the furnace length. This distance may vary for different installations. Along the conveyor, at intervals, which in a typical installation may be approximately four feet, are drop chutes through which the feed may be selectively discharged into the furnace by operating one or more openable and closeable gates installed at each chute location.

Conventional charging is such that usually the charge chute gates on individual chutes must be operated manually to open and close them in order to direct the feed to a particular zone, or zones, withinthe furnace in order to have the charge where and when it is desired during the smelting operation. In conventional practice, when the chute gates of a chute are opened and a particular zone has been adequately charged, the gates ofthat chute are closed, also manually, and those of an adjacent chute are opened and that zone charged until the length of furnace served by the chutes, on each side, has been charged.

In addition to the manipulation of the gates, an operator engaged in charging will normally rod the material into the furnace as it enters the chute, in order to keep the chute from plugging and to gain increased tonnage. That is, the material is pushed through the chute by a manually operated rod.

A furnace is considered ready for another charging cycle when enough of the feed, which to a great extent reposes along the sidewalls of the furnace, has smelted away and melts into the molten bath maintained in the furnace. This smelting away of the feed charge leaves room for additional feed material to be introduced along the sidewalls of the furnace. This cycle of charging is continually repeated while the furnace is in operation.

In conventional charging, the charging cycles are usually set up to achieve a compromise between a maximum of copper matte tonnage output and a charging crew of a reasonable number of men.

Side-charging, which has been briefly described above and as conventionally practiced in the industry is subject to a number of drawbacks, some of which are as follows:

3,244,298 Patented Apr. 5, 1966 (a) Since heat transfer within a furnace is largely a function of the dilference in temperature of the flame from the fuel burners and the charged feed, it follows that a frequently renewed layer of charge of limited thickness achieves greater fuel economy than that which results from less frequent charging, where the feed is piled to a greater depth along furnace sidewalls. Because charging frequency is limited by the practical considerations with respect to crew size, maximum utility of fuel for smelting is not attained.

(b) The manual rodding of feed into the furnace, an operation which almost invariably accompanies conventional side-charging, keeps certain furnace apertures open for extended periods. This causes infiltration of excessive amounts of cold air into the furnace, which retards the smelting rate.

(c) The men engaged in side-charging a reverberatory furnace normally work in close proximity to the furnace and are exposed for prolonged periods to the heat and fumes attendant to the smelting process.

This invention provides means and method for sidecharging a reverberatory furnace which overcome the drawbacks mentioned above. Furthermore, use of the charging system provided by the invention results in an increase in furnace smelting capacity.

In accordance with the invention a line or row of spaced drop chutes are provided in the furnace roof, or arch, along each side of and adjacent the furnace sidewalls, each chute being equipped with an openable and closeable charge gate. Installed within each chute, below the charge gate, is a pivoted deflector plate counterweighted in such a manner as normally to close the chute but to open it a certain amount during charging so that feed passing through the charge chute impinges upon the deflector and at the cessation of charging of material through that chute, the counterbalanced deflector plate automatically moves to closed position. The de flector plate is preferably positioned'so that it directs the feed passing through the charge chute further from the furnace sidewall than conventional side charging practice permitted, thus to cause the feed to be delivered at a place toward and nearer to the longitudinal center line of the furnace.

The charge gate of each chute in the preferred embodiment is provided with power driven means for open ing and closing the gate automatically and in timed sequence, although these gates are such that they may be operated manually in certain instances, if desired.

The charge chutes in each row of chutes located along each side of the furnace, are fed from storage bins by a suitable conveyor device, which may be of known construction; such for example, as the drag chain type in which a power driven endless drag chain moves feed material through a feed channel by means of paddles attached to the endless chain; the bottom wall of the channel being provided with charge openings at the charge chutes. Other suitable conveyor devices, if desired, may

be employed to carry the feed material to the chutes.

In accordance with a preferred embodiment of the in vention, the charge gate of each charge chute is automatically operated by mechanical linkage connecting the gate and the piston rod of an air cylinder, which is operated in timed sequence by compressed air. This opera tion is controlled by electrically operated solenoid valves installed in the compressed air lines connected to the air cylinders. Each air cylinder, in the battery of air cylinders and chutes on each side of the furnace, is connected to a four-way electrically operated solenoid valve, whichv is connected to a compressed air line, which in turn is connected to a source of compressed air. One leg of the valve, when opened by electrical impulse, directs compressed air momentarily to its associated air cylinder;

initiating a piston stroke which opens the chute gate. Having thus activated the cylinder piston, the compressed air is then diverted by the solenoid valve to an air manifold, covered and positioned so that it projects a blast of compressed air directly onto the furnace drag chain at a place directly over the mouth or feed opening of the charge chute. The purpose of this air blast is to blow into the chute over which it is located, any feed material that might otherwise adhere to the drag chain and carry over beyond the charge Zone for which it is intended. After a given interval of time, which may be regulated as described hereinafter, the solenoid valve operates to reverse the direction of flow of the compressed air to its air cylinder so that the piston of the air cylinder is retracted, which causes the chute gate to close and hence the passage of further feed through the charge chute is stopped. A few seconds before a chute gate is closed in this manner, the next chute in the charging sequence, activated and timed as hereinafter described, will open; and so the cycle will continue.

By means of a timer connected to each solenoid valve, the time interval between opening and closing a chute gate may be set for any prescribed or desired duration, thus permitting precise control of the time and hence the amount of feed that is directed through a particular charge chute.

In addition to an individual timer on each charge chute, a cycle timer is installed on each side of the furnace, for the purpose of governing and controlling the frequency of the charging cycle for the battery or row of chutes on that side. These cycle timers are connected in an electrical circuit in such a way that, when the set interval for the cycle has elapsed and another feed charging cycle is to begin, the drive motor which drives the endless drag chain conveyor is activated and the drag chain transports the feed material from suitable storage bins and carries it along the conveyor channel along the length of the furnace so that the feed may be delivered through the openings in the channel floor into the respective charge chutes. The duration of a charging cycle which has thus been initiated is governed by the accumulative settings of the individual chute timers since they regulate and control, in succession, the opening and closing of the charge gate chutes along the line of charge chutes on each side of the furnace, the successive opening and closing of the charge chutes being performed until the furnace is charged along the length of each row of chutes on each side of the furnace.

The charge chute located at the extreme end of the drag chain serves as a spill hole into which any carryover matter is discharged. This chute is preferably provided with an electric probe which indicates when this chute is full, in which case the material may be diverted to a different chute.

In preferred embodiments, the charging system of the invention may include switches for shifting to either automatic or manual control, signals and alarms to indicate failures or interruptions, air filters, lubricators, probes, automatic bin cleaning devices, and other auxiliary equipment.

Although the novel features which are believed to be characteristic of the invention are pointed out in the annexed claims, the invention itself, as to its objects and advantages and the manner in which it may be carried out, may be better understood from the following more detailed description taken in connection with the accompanying drawings, forming a part hereof, in which:

FIG. 1 is a plan view, partly diagrammatic, showing a reverberatory furnace to illustrate an installation embodying the invention;

FIG. 2 is a side view in elevation of the furnace illustrated in FIG. 1;

FIG. 3 is an end view in elevation of the furnace shown in FIGS. 1 and 2;

' FIG. 4 is a view in section to larger scale showing a typical charge chute unit of a row or battery of charge chutes mounted adjacent the sidewall of the furnace;

FIG. 5 is a view in elevation, on line 5-5 of FIG. 4, showing three typical charge chute units in the row or battery of chutes along one side of the furnace and showing the air cylinders and compressed air lines and control valves;

FIG. 6 is a view in elevation and partly in section, showing a typical air manifold located above the mouth of a charge chute;

FIG. 7 is a plan view to show the lower flight of a drag chain which travels in the feed conveyor channel along the furnace;

' FIG. 8 is a view in elevation, largely diagrammatic, to illustrate an entire row or battery of charge chutes mounted along one side of the furnace; and

FIGS. 9A and 9B, when placed together, is a diagram to illustrate the electrical circuits and hook-up for automatic operation and control of the charging system.

Referring now to the drawings, in which like reference characters throughout the several views indicate like parts, 17 indicates, generally for illustrative purposes, a reverberatory furnace for smelting copper ores or concentrates. The furnace may be constructed in usual known manner, having a bottom 18, sidewalls 27, 28 and a roof 29, which in this instance is arched. The bridgewall or burner end of the furnace is indicated at 53. It is unnecessary to show further details of the furnace itself since the general construction of copper reverberatory furnaces is well known to those skilled in the art.

In accordance with this invention a row, or battery, of novel chute units 1 to 16 inclusive is mounted along each side of the furnace. A battery of chutes 20 is mounted along one side and a battery Zita is mounted in similar fashion along the other side. They are of like construction but one may be considered as opposite hand to the other. So it will suffice, for purposes of description and illustration, to describe in detail only one of the batteries since it may be considered as typical.

Each battery is provided with a conveyor system for transporting feed material 19 from a hopper or bin 21, on to a travelling endless belt, or pan feeder 22 into a discharge chute 23 from which the feed material is delivered into a conveyor channel 24 which extends along the furnace in line with the row 2t) of charging chutes. In the bottom wall or floor of the conveyor feed channel there is an opening for each of the charge chutes through which feed passes into the charge chutes, one after another, at appropriate times, as described in further detail hereinafter. A travelling endless drag chain conveyor 25, driven by electric motor 26, drags the feed material along this channel for discharge through the channel floor openings. This type of feeder, bins, and drag chain conveyors, is known in the art.

A typical charge chute unit is shown perhaps best in FIG. 4 and since all of the charge chute units are of similar construction and mounted in similar fashion it will suffice to describe only one, as typical. The arched roof 29 adjacent furnace sidewall 27 is provided with a row of rectangular charge ports, a typical charge port 30 being shown in FIG. 4. These charge ports are somewhat larger than has been usual practice, heretofore. Extending into the port St} is the lower or discharge end portion 31 of the charge chute, designated generally by reference numeral 32. The chute is of generally rectangular cross-section and constructed of suitable steel plate material. The lower end portion of the chute extends through a cast sealing member 33 which rests on the roof Wall and provides an air tight seal surrounding the chute. A chute throat portion 34, flared outwardly in upward direction, is mounted above a deflector plate box portion 35 which in turn is secured to the upper end of the chute discharge end portion 31. Mounted within the box portion 35 at its upper end is a pivotally mounted deflector plate 36. This deflector plate is fixedly secured along one of its edges to a rocker shaft 37 extending through suitable bearing apertures in the sidewalls 38, 39 of the deflector plate box 35. Secured to the outer end 40 of the rocker shaft 37 (see FIGS. 4 and 5) is the inner end of a lever member 41. A counterweight 42 is suspended from the outer end of the lever 41 by means of a hook 43 extending through a suitable aperture 44 near the outer end of the lever. The counterweight is such that it normally maintains the deflector plate closed. In FIG. 4 the deflector plate is shown in inclined position merely for clarity of disclosure, but its normal position, when no feed material is being dropped upon it, is in horizontal or closed position which closes the chute. Its full open position is shown in dotted lines in FIG. 4. Now it will be seen that when feed material is dropped through the throat 34 of the chute, the deflector plate will assume a position, the inclination of which will be determined by the weight or force of the material impinging upon it balanced against the weight of the counterbalance member 42.

Extending through a suitable opening in the cover plate 45 which closes the top end of flared throat portion 34 of the chute, is a chute entry portion 46. The chute portion 46 communicates with a rectangular mouth or feed drop opening 47 in the floor or bottom wall 48 of the conveyor feed channel 24 which channel comprises bot-tom wall 48 and sidewalls 49, 50. As mentioned above, there is a row of these feed drop openings along the floor of the channel 24. As shown in the illustrative embodiment, these openings are spaced at intervals of about four feet along the channel. Floor plates 51 of wear resistance material and resting on the bottom wall of the channel, span the distance between successive channel drop openings 47.

A pivoted drop gate 52 mounted on a rocker shaft 60 is operative to close the feed drop opening 47 and to open it. The drop gate is shown in open position in FIG. 6 to permit material transported in the conveyor feed channel, to pass through it, then through its communicating chute entry portion 46, into the throat portion 34. The feed material is dragged along the floor of the conveyor channel by the paddles 55 of the lower flight 56 of the drag chain 25 which travels in the direction of arrow 57, the upper flight 58 of the drag chain, of course, travelling in the opposite direction. Idler rolls 59 (see FIG. 4) are mounted at intervals along the length of the endless drag chain. The drag chain is trained over end pulleys, one of which is driven by a motor 26, as mentioned above. The drop gate 52 is fixedly mounted along one of its edges on a rocker shaft 66 which extends through bearing'apertures in the sidewall structural members 49, 50 of the conveyor feed channel. The outer end of this shaft is squared to form a key 61 upon which is keyed, at one end, a link lever 62. The outer end of this lever (see FIG. 5) is pivotally connected to the outer end 63 of the piston rod 64 of an air cylinder 65. At its after end, the air cylinder 65 is piv-otally mounted at 66 on a mounting bracket 67 which is secured to the structural sidewall members of the channel sidewall 49. Now it may be observed that on the forward stroke of the piston of air cylinder 65, the piston rod 64, rotates shaft 60, through the link lever 62 to move the pivoted drop gate 52 to open position; as shown at the chute in thecenter of FIG. 5. And when the piston is retracted in cylinder 65 the drop gate 52 is moved to closed position; as hown at the chute at the right hand of FIG. 5. t

Each of the air cylinders 65 is connected to a source of compressed air. The after end of the cylinder is connected by a conduit 70 through a solenoid operated fourway valve 71; the forward end of the cylinder being connected by a conduit 72 through the same solenoid valve;

'this valve being connected to a compressed air header 73 by pipe '74. Connected to compressed air conduit 70 is a branch conduit '75 which connects with a compressed air 6 a jet manifold 76, over which is mounted a deflecting shield 77. The air manifold is poistioned directly above the feed drop opening 47 and has a plurality of air jet holes 68 so that compressed air passing through conduit 75 is constrained to flow through the air jets downwardly into the opening 47. Air is forced through the air jets as an air blast at the appropriate time to blow any feed material, which might otherwise cling to the drag chain, into the charge chute when the drop gate 52 is in open position. When the piston of air cylinder 65 is retracted, the air blast through manifold 76 is shut off because the compressed air is then flowing in line 72 and not in line 70. Conduit 70 is provided with a lubricator 78 connected by pipe 79 to a header pipe 80 which carries lubricating oil from a suitable source, for lubricating the air cylinder 65.

As previously described, the drop gate 52 for each charge chute in the battery of units (1 to 16) on each side of the furnace, is operated pneumatically by an associated solenoid valve 71 which controls the supply of air pressure to the air cylinder for that charge chute. The sole noid valve for each charge chute is in turn electrically actuated for a predetermined period of time by an associated timer mechanism. The timer for a particular charge chute unit thus determines the length of time that the drop gate for the unit remains open once its corresponding solenoid valve is energized.

The individual timers controlling the operation of the respective charge chute units are arranged in an electrical circuit in such a manner that they are operated sequential ly during the cyle of charging operation; i.e., each of the charge chutes in the battery will open and close one after the other, from the first to the last, until a charging cycle is completed by the closing of the last chute in the battery. The initiation of such a charging cycle is under the control of a master or cycle timer which is preset to commence a charging cycle at predetermined periods of time. Although the cycle timer determines the instant in time at which the charging cycle for one side of the furnace is initiated, it should be noted that the duration of the charging cycle will be determined by the cumulative settings of the individual timers controlling the operation of their respective charge chute units.

FIGS. 9A-9B, when placed together, is an electrical schematic diagram illustrating a suitable circuit arrangement for accomplishing the above-described sequence of events in the automatic control of the charge chute units for the reverberatory furnace. In addition to circuitry for controlling the timed, sequential operation of the battery of charge chute units on one side of the furnace, the diagram also includes numerous contactors for regulating the compressed air supply and for actuating signals and alarms indicating failures or interruptions in the electrical supply, switches for shifting the furnace between automatic and manual control, as well as various other circuit elements for controlling air filters, lubricators, automatic bin cleaning devices, and other auxiliary equipment. Since the function, construction, and operation of such elements are well known, and their incorporation into the control circuit may be readily understood without difliculty by those having skill in the art, it is considered not necessary that these conventional elements, shown in the diagram for the sake of comprehensiveness, be identified or described further herein.

As shown in FIGS. 9A-9B a cycle timer 100, which in the illustrative embodiment shown may typically be an Eagle Timer type HP-57A6, is utilized for initiating and controlling the frequency of the charging cycle for the battery of charge chutes on each side of the furnace. When a charging cycle is commenced, as determined by the setting of the cycle timer 100, appropriate contacts are closed for starting the drag chain conveyor 25 and for completing an energizing circuit to timer 116 (see also FIG. 8). Timer 116, which exemplarily may be an Eagle Timer type HP54A6, in turn energizes'solenoid S16, which thereupon actuates an associated pneumatic valve 71 (see FIG. 5), thus passing compressed air through pipe .74) and openingthe drop gate 52 associated with charge compressed air flows through branch pipe '75 to blow a blast of air through the manifold 76 of unit 16 into the drop opening 47 of thatunit to blow the feed material into. the throat of the opened chargechute of that unit.

Upon. the completion of the charge cycle for this unit, as

determined'by the settingof its correspondingtimer 116,

'solenoid S16 is deenergized, causing compressed air to flow through pipe 72, to retract the piston of the air cylinder for unit 16 to close drop gate 52 of this unit and meantime the. air blast through the manifold is shut off. In addition to the. termination of thecharging for unit 16, an energizing circuit is completed to timer 115 controlling the next adjacent charge chute unit in the battery, i.e.,

unit 15,

The actuation of timer 115, which may; be of a type the associated drop gate, for the charge unit 15 to open and remain-openfor a predetermined duration according to the setting of its timer and in a manner described above in connection with the operation of charge unit 16.. Thus unit 15' goes through a similar cycle, asunit i6; terminating in the closingof its drop gate and the stopping of the air blast. In similar manner the drop gates for each of the individual charge chutes in the battery are opened for a predetermined length of time, one after the other, for an interval determined by the setting of their respective timers 11 6, 115 102, 101 and closed in sequence one after the other.

When the last charge chute unit in the battery, i.e unit 1, has been, actuated, and its associated timer 101 has completed its cycle of operation, certain circuitry,

whichmay be traced through the coil and associated contactsof normally-closed contacts NI-ll and AM TD, is made operative for stopping the drag chain 25. Thereafter the apparatusproviding automatic charging of the reverberatory furnace remains in a quiescent state, with the drop gates of all charge chutes in the battery closed and thedragchain 2,5 atrest, until the cycle timer 1% again initiatesanother cycle of charging operation.

In addition to,the-conventional circuitelementsshown inEIGS. 9A9B, for providing. manual override, alarm signals, etc, theillustrative embodiment of the present invention shown in the diagram includes an electrical probing device 120, positioned in the charge chute unit located atv the extreme end of the drag chain conveyor. 25, for indicatingwhenever this.chute,,which.acts as a spill hole, is fullof carry-over material, whereupon. an appropriate circuit. is 'actuatedfor diverting material to a different chute It may now be observed from the foregoing description that the invention provides, an automatic syste-mfor side charging a, reverberatory furnace thus. eliminating the necessity for a'large operating crew. In fact, by the use of this system,,the charging of as many as three reverberatory furnaces at any, desired interval, even continuously, may. be accomplished with only the part-time attention of. a single operator. This shows the tremendous advantage over the conventional prior. art. method previously practiced in operating the same furnaces which required a crew of six operators forv continuous manual charging. Furthermore, theoperating men need not be exposed to the heat andfume asformerly was. the case.

In addition, the automatic charging accomplished by this invention provides improved heat. transfer and the elimination of a; source of cold air. infiltration into the furnace. A material increase in furnace smelting capacity has resulted;

The terms and expressions which have been employed herein are used as terms of description and not: of limitation, and thereisno intension,.in theuse of: such terms and expressions, of excluding any equivalents of the features. shown and described. or portions thereof, but it is recognized that various modifications. are possible within the scopeof the invention claimed.

What is. claimed is:

1'. Apparatus for charging feed" material to a metallurgical'furnace having, a topand side walls and a. row of charge ports,in the top,wall along its length, which comprises conveyor means including a feed delivery channel above said row, of charge ports having a horizontally disposed bottom wall and an endless power, driven travelling drag chain for moving feed charge in said channel along saidbottom wall, means defining a feed drop opening in said bottom wall of said channel for each of said chargeports, each of said feed drop'openings being above and registering with its associated charge port, a vertically disposedcharge chute for each of said charge ports, said charge chute, comprising, an upper portion communicating with its feed drop opening, and a lower portion communicating with its charge port, and an intermediate portion between said upper and lower portions, a hinged drop gate for each of said feed drop openings, said drop gate being mounted to be swung to open position in said upper portion of its chute to open its feed drop opening and to closed position to close its feed drop opening, said gate when closed lying in a plane substantially flush with the bottom wall of said 'feed delivery channel, power operated means for each of said" drop gates, said power operated means being connected to its drop gate and-being operative to open and close its drop gate, an electric circuit, and time control means connected in said circuit for each of said drop gates and operated by' electric power for; controlling the poweroperated means for opening and closing its drop gate at predetermined intervals.

2. Apparatus for charg-ing feedmateri-al to a metallurgical furnace having atop; and side walls anda row of charge ports in said" top wall along and adjacent a side wall of saidfurnace, which comprises feed charge conveyor means including a feed charge delivery channel along saidrowof charge ports having a horizontally disposed bottom wall above said row of charge ports and} anendless power drivendrag chain travelling in said channel along itsj-bottom wall, meansdefining a feed drop openingin the; bottom wall of said feeddelivery channel for each of said charge' ports, each of said feed drop openings registering with its associated charge port, said drag chainbeingope-r-ative to deliver feed material along .the :bottornwall'of saidchannel to each of said feed drop openings, a charge chute for each of said charge ports, said charge chute, comprising, an upper portion communicating with its feed drop opening, a lower portion communicating with its charge port, and an intermediate portion connectingsaid' upper and lower portions, a hingeddrop gate, for each of said feed drop openings, sa-id'drop gate being mounted to be moved-in said upper portion to open position to open its feed-opening and to closed position to close its feed opening, said drop gate, when in closed position, lying flush witht-he bottom wall of said delivery channel, a counterbalanced hinged defiector plate for. each of said' chutes, said deflector plate being positioned within the intermediate portion of the chute between its drop gate and its charge port and mounted to be moved. to closed position to close the intermediate pontion ofv its chute when its drop gate is closed and to open position to open the intermediate portion of its chute when its drop gate is open, said deflector plate being counterbalanced to be closed in normal position and to be moved" by the force of'feed charge dropped thereon through, its feed'drop openingto a position which deflects the feed charge dropped thereon in a direction away from the side wallof'said furnace along which said row of charge ports is positioned, power operated means including an air cylinder, piston and linkage for each of said drop'gates, said linkage being connected to its drop gate and being operative to open and close its drop gate upon reciprocation of said piston, an electric circuit connected to a source of electric power, unit time control means connected in said circuit for each of said power operated means, means operative in response to operation of its unit time control means to control the opera- .tion of said power operated means whereby its drop gate may be opened and closed at predetermined intervals by the power operated means and air blast means mounted adjacent to and above each of said feed drop openings operative to blow a blast of air downwardly through its adjacent feed drop opening when its drop gate is in open position.

3. Apparatus according to claim 2 which includes a cycle timer means connected in said electric circuit controlling the cycle of operations of the unit time control means.

4. Apparatus according to claim 2 in which said deflector plate is pivot-ally mounted and counterbalanced to maintain its chute closed when the drop gate of that chute is in closed position and to be opened by impingement thereon of feed material passing through its feed opening when its drop gate is in open position and in which a solenoid valve controls the operation of said air cylinder and air blast means.

5. Apparatus for charging feed material to a reverberatory furnace having a row of charge ports in the roof thereof adjacent a sidewall, which comprises a feed channel having a bottom wall above said charge ports extending along said row of charge ports, a feed opening in said bottom wall above each of said charge ports, an endless drag chain conveyor mounted with its lower flight travelling in said feed channel for delivering feed material to said feed openings, a vertically disposed charge chute for each of said charge ports, having a throat portion at its upper end and a discharge portion at its lower end, said throat portion communicating with its feed opening and said discharge portion communicating with its charge port, a drop gate for each of said feed openings, a rocker shaft pivotally mounting said drop gate adjacent its feed opening and operative to move said drop gate to open position to open its feed opening and to closed position to close its feed opening, an air cylinder having a reciprocating piston and rod for each of said drop gates, linkage means connecting the piston rod with the rocker shaft of its drop gate, said rod on its forward stroke rocking said shaft to move its drop gate to open position and on its rearward stroke rocking said shaft to move its drop gate to closed position, a compressed air header connected to a source of compressed air, a four-way solenoid valve for each of said charge chutes, a first conduit conneoted to said header and to said valve, a second compressed air conduit connected to said four-way valve and to one end of said air cylinder, at third compressed air conduit connected to said four-way valve and to the other end of said air cylinder, an electric circut, an electrically operated uni-t timer for each of said chutes connected in said circuit and to its solenoid valve to cause said solenoid valve to operate at timed intervals to pass com pressed air through said second compressed air conduit to its air cylinder to move its piston rod to open its drop gate and then through said second compressed air conduit to move its piston rod to close its drop gate at timed intervals.

6. Apparatus according to claim 5 in which an electrically opera-ted cycle timer is connected in said electric circuit to control the cycle of operation of said unit timers.

7. Apparatus according to claim 5 which includes a fourth compressed air conduit connected to said second compressed air conduit and an air manifold mounted over the feed opening of its chute connected to said fourth compressed air conduit for directing a blast of air into its feed opening when its drop gate is in open position.

8. Apparatus according to claim 7 in which an electrically operated cycle timer is connected in said electric circuit to control the cycle of operation of said unit timers.

9. Apparatus for charging feed material to a reverberatory furnace having a row of charge ports in the roof thereof adjacent a sidewall, which comprises a feed channel having a bottom wall above said charge ports extending along said row of charge ports, a feed opening in said bottom wall above each of said charge ports, an endless drag chain conveyor mounted with its lower flight travelling in said feed channel for delivering feed material to said feed openings, a vertically disposed charge chute for each of said charge ports, having a throat portion at its upper end, a discharge portion at its lower end and a deflector box portion intermediate said throat and discharge portions, said throat portion communicating with its feed opening and said discharge portion communicating with its charge port, a pivoted deflector plate mounted within said box portion to move to closed position to close said chute and to open position to open said chute, said deflector plate being counterbalanced to move said plate to normal closed position and to move toward open position when feed material is passed through its overlying feed opening, a drop gate for each of said feed openings, a rocker shaft pivotally mounting said drop gate adjacent its feed opening and operative to move said drop gate to open position to open its feed opening and to closed position to close its feed opening, an air cylinder having a reciprocating piston and rod for each of said drop gates, linkage means connecting the piston rod with the rocker shaft of its drop gate, said rod on its forward stroke rocking said shaft to move its drop gate to open position and on its rearward stroke rocking said shaft to move its drop gate to closed position, a compressed air 7 header connected to a source of compressed air, a fourway solenoid valve for each of said charge chutes, a first conduit connected to said header and to said valve, a second compressed air conduit connected to said fourway valve and to one end of said air cylinder, a third compressed air conduit connected to said four-way valve and to the other end of said air cylinder, an electric circuit connected to a source of electric power, a unit timer for each of said chutes connected in said circuit and to its solenoid valve to cause said solenoid valve to operate at timed intervals to pass compressed air through said second compressed air conduit to its air cylinder to move its piston rod to open its drop gate and then through said second compressed air conduit to move its piston rod to close its drop gate at timed intervals.

10. Apparatus according to claim 9 which includes -a fourth compressed air conduit communicating with said solenoid valve and an air manifold mounted over the feed opening for its chute connected to said fourth compressed a-ir conduit for directing a blast of air through the feed opening into its chute when its drop gate is in open position.

11. Apparatus according to claim 10 which includes an electrically operated cycle timer connected in said electric circuit to control the cycle of operation of said unit timers.

References Cited by the Examiner UNITED STATES PATENTS 1,559,511 10/1925 Church 214-18 1,857,592 5/1932 Hawkins et al. 21418 2,311,747 2/1943 Gooch.

2,603,342 7/1952 Martinson 214-17 X 2,861,840 11/1958 Powischill et al. 302-19 X 3,133,797 5/1964 Pierson 302-19 X GERALD M. FORLENZA, Primary Examiner. HUGO O. SCHULZ, Examiner. 

1. APPARTUS FOR CHARGING FEED MATERIAL TO A METALLURGICAL FURNACE HAVING A TOP AND SIDE WALLS AND A ROW OF CHARGE PORTS IN THE TOP WALL ALONG ITS LENGTH, WHICH COMPRISES CONVEYOR MEANS INCLUDING A FEED DELIVERY CHANNEL ABOVE SAID ROW OF CHARGE PORTS HAVING A HORIZONTALLY DISPOSED BOTTOM WALL AND AN ENDLESS POWER DRIVEN TRAVELLING DRAG CHAIN FOR MOVING FEED CHARGE IN SAID CHANNEL ALONG SAID BOTTOM WALL, MEANS DEFINING A FEED DROP OPENING IN SAID BOTTOM WALL OF SAID CHANNEL FOR EACH OF SAID CHARGE PORTS, EACH OF SAID FEED DROP OPENINGS BRING ABOVE AND REGISTERING WITH ITS ASSOCIATED CHARGE PORT, A VERTICALLY DISPOSED CHARGE CHUTE FOR EACH OF SAID CHARGE PORTS, SAID CHARGE CHUTE, COMPRISING, AN UPPER PORTION COMMUNICATING WITH ITS FEED DROP OPENING, AND A LOWER PORTION COMMUNICATING WITH ITS CHARGE PORT, AND AN INTERMEDIATE PORTION BETWEEN SAID UPPER AND LOWER POR- 